Overlay visuals and windows are not common across a wide spectrum of X servers yet. With the implementation of overlay visuals now properly understood and a standard convention for advertising such visuals available, overlays in X should become a common capability of high-end X servers.
Hopefully the information in this article has provided programmers with enough information to start experimenting with overlays in X and integrating overlay support into their applications. It is also hoped X users will begin demanding overlay support in their X servers and enjoy the advantages of overlays in their everyday work.